
function one() {
    //创建one的词法环境
    var a = 1;
    return function two() {
        //创建two的词法环境
        var b = 2;
        //let scopes = [two的词法环境, one的词法环境];
        //创建three这个函数 new FunctionInstance(three,'console.log(a, b);',scopes);
        return function three() {
            console.log(a, b);
        }
    }
}

let two = one();
let three = two();
